Table S1 Total alkalinity (TA, μeq kg-1) and dissolved inorganic carbon (DIC, μmol kg-1) in December 2010 from open ocean at Sheltered Reef. Each value is an average of 2 replicate samples from the same Niskin bottle. The standard deviations (SD) for the sets of three Niskins each day indicate that the open ocean end-member was chemically uniform

6-Dec / 7-Dec / 8-Dec / 6-Dec / 7-Dec / 8-Dec
TA #1 / 2494.5 / 2500.1 / 2497.0 / DIC #1 / 2101.0 / 2104.9 / 2108.5
TA #2 / 2495.2 / 2501.8 / 2493.8 / DIC #2 / 2102.8 / 2103.6 / 2111.7
TA #3 / 2496.4 / 2501.6 / 2494.0 / DIC #3 / 2099.3 / 2106.3 / 2110.0
Average / 2495.4 / 2501.2 / 2494.9 / Average / 2101.0 / 2104.9 / 2110.0
SD / 0.94 / 0.94 / 1.77 / SD / 1.72 / 1.33 / 1.59
% SD / 0.04% / 0.04% / 0.07% / % SD / 0.08% / 0.06% / 0.08%

Table S2 Average daytime net community calcification (NCC) and net community productivity (NCP) rates (mmol m-2 h-1) and environmental data, including percent calcifier cover (%CC), aragonite saturation state (omega), and photosynethetically active radiation (PAR, μE m-2 s-1) for several field and mesocosm studies with details regarding how data were sourced

Reference / Location / Method / Community / Data sources and assumptions
This study / Red Sea / Eulerian Flow Respirometry / 4% Live Coral, 57% CCA / Average of all hourly daytime estimates
Falter et al. 2012 / Ningaloo Reef Flat / Controlled Volume Alkalinity Anomaly / Reef flat, 50-90% coral cover / Wa and NCC from original data, average of the daytime hourly values, Temperature and PAR from Table 2 in Falter et al. 2012.
Shaw et al. 2012 / Lady Elliot Island, Great Barrier Reef / Slackwater / Southern lagoon had a sand bottom with high (we estimate approximately 40%) coral cover throughout / Wa, Temperature, and NCC from original data, average of the daytime hourly values.
Shamberger et al. 2011 / Kaneohe Bay, Oahu, Hawaii / Alkalinity Anomaly-Residence time and Box-model / Barrier Reef, 20-30% coral cover, abundant CCA and macroalgae / Wa and NCC from original data, average of the daytime hourly box-model values, Temperature and PAR from Table 1 in Shamberger et al. 2011.
Bates et al. 2010 / Hog Reef Flat, Bermuda / Buoyant weight and alkalinity anomaly-residence time / Rim reef has 21% coral cover / Wa and NCC calculated from data reported in Table 3 of Bates et al. 2010. Divided daily rates by number of daylight hours to calculate hourly rates, assuming nighttime rates are near zero. Temperature from Table 3. Averaged according to the seasons described on page 2521.
Silverman et al. 2007a,b / Gulf of Eilat / Eulerian Flow Respirometry / 10% calcifier cover, by pers. Comm. / Wa, Temperature, and NCC from original data, average of the daytime hourly values.
Yates and Halley 2006 / Molokai Reef Flat, Hawaii / Enclosed incubation chamber with alkalinity anomaly technique / Patch reef with 10% coral cover / Wa, Temperature, PAR, and NCC from Table 1 in Yates and Halley 2006, average of the daytime hourly values.
Patch reef with 22% coral cover
Patch reef with 10% coral cover
Watanabe et al. 2006 / Palau Barrier Reef / Flow respirometry / Flat: 1.4% live coral, 15 % brown algae / Wa from Table 3 in Watanabe et al. 2006. Temperature and Reef Flat NCC from Table 5 in mmol m-2 day-1. Divided daily rates by number of daylight hours to calculate hourly rates, assuming nighttime rates are near zero. PAR from Figure 2, by estimating the area of a triangle.
Ohde and van Woesik 1999 / Rukan-sho, Ryukyu Islands, Okinawa, Japan / Slackwater, daytime sampling / 36% coral cover on reef flat and sandy lagoon / Hourly NCC rates from Table 4 of the Ohde and van Woesik 1999. Wa and Temperature are average daytime values from Table 3.
Gattuso et al. 1997 / Moorea, French Polynesia / Alkalinity Anomaly in enclosure / Primary calcifiers were CCA, forams, mollusks, 85% macroalgae, plus rhodophyta / Wa reported on page 734 and Temperature in Table 1 (not specified as daytime). PAR and daytime NCC estimated from data in Figure 4.
Gattuso et al. 1996 / Moorea, French Polynesia / Lagrangian Flow Respirometry / Two communities: seaward: coral dominant with 4-17% CCA; backreef: 1-2% coral, 9-21% CCA / Wa calculated from pH and total Alkalinity reported in Table 2. Temperature reported in Table 2. PAR and daytime hourly NCC estimated from data in Figure 3.
Yong Reef, Great Barrier Reef / 30% coral cover, primarily Acropora spp., some CCA
Andersson et al. 2009 / Hawaii Institute of Marine Biology / Alkalinity Anomaly / Coral (Montipora spp.) and rhodoliths cover 20-30% of surface area, CCA covers 25% of walls / Wa, Temperature, and NCC are averages of the reported daytime, hourly values report in Table 1.
Langdon and Atkinson 2005 / Hawaii Institute of Marine Biology / Alkalinity Anomaly / 100% coral cover, Porites compressa and Montipora verucosa (capitata) / Wa, Temperature, PAR, and NCC based on control and treatment runs without nutrient enrichment, reported in Table 3.
Langdon et al. 2000 / Biosphere 2 / Alkalinity Anomaly / 3% coral cover, CCA is primary calcifier (~40%) / Wa reported on page 644. Constant temperature reported on page 640. PAR based on data in Table 4. NCC reported on 645, in daily units. Divided by 12 hours of daylight because experiments were very long (months/years).
Langdon 2002 / Biosphere 2 / Alkalinity Anomaly / 3% coral cover, CCA is primary calcifier (~40%) / Wa and NCC reported in Table 3. Averaged treatment replicates, divided by 12 hours in a day.

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